Substituted 2,4-diamino-1,3,5-triazines as herbicides

ABSTRACT

The invention relates to novel substituted 2,4-diamino-1,3,5-triazines of the formula (I)                    
     in which 
     R 1  represents (in each case unsubstituted) phenyl or naphthyl 
     R 2  represents alkyl, 
     R 3  represents hydrogen, represents halogen or represents in each case optionally substituted alkyl, alkoxy, alkylthio, alkylsulphinyl or alkylsulphonyl, 
     R 4  represents hydrogen, represents halogen or represents optionally substituted alkyl, 
     R 5  represents hydrogen, represents halogen or represents optionally substituted alkyl, and 
     R 6  represents hydrogen or represents in each case optionally substituted alkyl, alkylcarbonyl or alkylsulphonyl, 
     (but where the compound 2-amino-4-(1-phenyl-ethylamino)-6-trifluoromethyl-1,3,5-triazine is excluded), 
     to processes for preparing the novel compounds and to their use as herbicides.

This is a 371 National Application of PCT/EP98/01362, filed Mar. 9,1998.

The invention relates to novel substituted 2,4-diamino-1,3,5-triazines,to processes for their preparation and to their use as herbicides.

A number of substituted 2,4-diamino-triazines, such as, for example, thecompound2-amino-4-(1-phenyl-ethylamino)-6-trifluoromethyl-1,3,5-triazine, arealready known from the (patent) literature (cf. U.S. Pat. No. 3,816,419,cf. also U.S. Pat. No. 3,932,167, EP 191496, EP 273328, EP 411153/WO90/09378). However, these compounds have hitherto not attained anyparticular importance.

This invention, accordingly, provides the novel substituted2,4-diamino-1,3,5-triazines of the general formula (I),

in which

R¹ represents (in each case unsubstituted) phenyl or naphthyl,

R² represents alkyl,

R³ represents hydrogen, represents halogen or represents in each caseoptionally substituted alkyl, alkoxy, alkylthio, alkylsulphinyl oralkylsulphonyl,

R⁴ represents hydrogen, represents halogen or represents optionallysubstituted alky,

R⁵ represents hydrogen, represents halogen or represents optionallysubstituted alkyl, and

R⁶ represents hydrogen or represents in each case optionally substitutedalkyl, alkylcarbonyl or alkylsulphonyl,

but where the known compound2-amino-4-(1-phenyl-ethylamino)-6-trifluoromethyl-1,3,5-triazine (cf.U.S. Pat. No. 3,816,419) is excluded by disclaimer.

The novel substituted 2,4-diamino-1,3,5-triazines of the general formula(I) are obtained when

(a) substituted biguanides of the general formula (II)

in which

R¹, R² and R⁶ are each as defined above

and/or acid adducts of compounds of the general formula (II)

are reacted with alkoxycarbonyl compounds of the general formula (III)

in which

R³, R⁴ and R⁵ are each as defined above and

R represents alkyl,

if appropriate in the presence of a reaction auxiliary and ifappropriate in the presence of a diluent,

or that

(b) to prepare compounds of the formula (I) in which R⁶ is differentfrom hydrogen

2,4-diamino-1,3,5-triazines of the general formula (Ia)

in which

R¹, R², R³, R⁴ and R⁵ are each as defined above

are reacted with alkylating, acylating or sulphonylating agents of thegeneral formula (IV)

X−R⁶  (IV)

in which

R⁶ is as defined above, except for hydrogen, and

X represents halogen, alkoxy, acyloxy or alkoxysulphonyloxy,

if appropriate in the presence of a reaction auxiliary and ifappropriate in the presence of a diluent,

and further conversions within the scope of the above definition ofsubstituents are carried out by customary methods, if appropriate, onthe compounds of the general formula (I) obtained according to theprocesses described under (a) or (b).

The novel substituted 2,4-diamino-1,3,5-triazines of the general formula(I) have strong and selective herbicidal activity.

Surprisingly, the 2,4-diamino-1,3,5-triazines of the general formula (I)according to the invention exhibit considerably stronger herbicidalactivity than the prior-art compound2-amino-4-(1-phenyl-ethylamino)-6-trifluoromethyl-1,3,5-triazine, andsome of them are tolerated well by crop plants, such as, for example,barley and cotton.

The compounds of the general formula (I) according to the inventioncontain at least one asymmetrically substituted carbon atom and cantherefore be present in different enantiomeric (R- and S-configuredforms) and/or diastereomeric forms. The invention relates both to thevarious possible individual enantiomeric or stereoisomeric forms of thecompounds of the general formula (I) and to the mixtures of theseisomeric compounds.

In the definitions, the hydrocarbon chains, such as alkyl, are in eachcase straight-chain or branched, including combination with heteroatoms,such as in alkoxy or alkylthio.

Halogen generally represents fluorine, chlorine, bromine or iodine,preferably fluorine, chlorine or bromine, in particular fluorine orchlorine.

The invention preferably provides compounds of the formula (I) in which

R¹ represents (in each case unsubstituted) phenyl or naphthyl,

R² represents alkyl having 1 to 6 carbon atoms,

R³ represents hydrogen, represents halogen or represents in each caseoptionally halogen- or C₁-C₄-alkoxy-substituted alkyl, alkoxy,alkylthio, alkylsulphinyl or alkylsulphonyl having in each case 1 to 6carbon atoms,

R⁴ represents hydrogen, represents halogen or represents optionallyhalogen-substituted C₁-C₆-alkyl,

R⁵ represents hydrogen, represents halogen or represents optionallyhalogen-substituted C₁-C₆-alkyl, and

R⁶ represents hydrogen or represents in each case optionally halogen- orC₁-C₄-alkoxy substituted C₁-C₆-alkyl, C₂-C₇-alkylcarbonyl orC₁-C₆-alkyl-sulphonyl,

but where the known compound2-amino-4-(1-phenyl-ethylamino)-6-trifluoromethyl-1,3,5-triazine (cf.U.S. Pat. No. 3,816,419) is excluded by disclaimer.

The invention relates in particular to compounds of the formula (I) inwhich

R¹ represents (in each case unsubstituted) phenyl or naphthyl,

R² represents methyl, ethyl, n- or i-propyl, n-, i-, s- or t-butyl,

R³ represents hydrogen, represents fluorine, chlorine, bromine, orrepresents in each case optionally fluorine-, chlorine-, methoxy- orethoxy-substituted methyl, ethyl, n- or i-propyl, n-, i-, s- or t-butyl,methoxy, ethoxy, n- or i-propoxy, n-, i-, s- or t-butoxy, methylthio,ethylthio, n- or i-propylthio, n-, i-, s- or t-butylthio,methylsulphinyl, ethylsulphinyl, methylsulphonyl or ethylsulphonyl,

R⁴ represents hydrogen, represents fluorine, chlorine or bromine, orrepresents in each case optionally fluorine- and/or chlorine-substitutedmethyl, ethyl, n- or i-propyl, n-, i-, s- or t-butyl,

R⁵ represents hydrogen, represents fluorine, chlorine or bromine, orrepresents in each case optionally fluorine- and/or chlorine-substitutedmethyl, ethyl, n- or i-propyl, n-, i-, s- or t-butyl, and

R⁶ represents hydrogen or represents in each case optionally fluorine-,chlorine-, methoxy- or ethoxy-substituted methyl, ethyl, n- or i-propyl,n-, i-, s- or t-butyl, acetyl, propionyl, n- or i-butyroyl,methylsulphonyl, ethylsulphonyl, n- or i-propylsulphonyl, n-, i-, s- ort-butylsulphonyl,

but where the known compound2-amino-4-(1-phenyl-ethylamino)-6-trifluoromethyl-1,3,5-triazine (cf.U.S. Pat. No. 3,816,419) as excluded by disclaimer.

The abovementioned general or preferred radical definitions apply bothto the end products of the formula (I) and, correspondingly, to thestarting materials or intermediates required in each case for thepreparation. These radical definitions can be combined with each otherat will, i.e. including combinations between the given preferred ranges.

Using, for example, 1-(1-phenyl-propyl)-biguanide and methyltrifluoroacetate as starting materials, the course of the reaction ofthe process (a) according to the invention can be illustrated by thefollowing equation:

Using, for example,2-amino-4-(2,2,2-trifluoro-1-methyl-ethyl)-6-(1-phenyl-ethyl-amino)-1,3,5-triazineand acetyl chloride as starting materials, the course of the reaction inthe process (b) according to the invention can be illustrated by thefollowing equation:

The formula (II) provides a general definition of the substitutedbiguanides to be used as starting materials in the process (a) accordingto the invention for preparing the compounds of the formula (I). In theformula (II), R¹, R² and R⁶ each preferably or in particular have thosemeanings which have already been mentioned above in connection with thedescription of the compounds of the formula (I) according to theinvention as being preferred or as being particularly preferred for R¹,R² and R⁶.

Suitable acid adducts of compounds of the formula (I) are their additionproducts with protonic acids, such as, for example, with hydrogenchloride, hydrogen bromide, sulphuric acid, methanesulphonic acid,benzenesulphonic acid and p-toluene-sulphonic acid.

The starting materials of the general formula (II) are known and/or canbe prepared by a process known per se (cf. U.S. Pat. No. 3,816,419;Indian J. Chem. 1 (1963), 218-220; J. Am. Chem. Soc. 81 (1959),3728-3736).

The substituted biguanides of the general formula (II) are obtained whenamines of the general formula (V)

in which

R¹ and R² are each as defined above

and/or acid adducts of compounds of the general formula (V), such as,for example, the hydrochlorides

are reacted with cyano guanidines of the general formula (VI)

in which

R⁶ is as defined above,

if appropriate in the presence of a reaction auxiliary, such as, forexample, hydrogen chloride, and if appropriate in the presence of adiluent, such as, for example, n-decane, toluene or1,2-dichloro-benzene, at temperatures between 100° C. and 200° C. (cf.the preparation examples).

The formula (III) provides a general definition of the alkoxycarbonylcompounds further to be used as starting materials in the process (a)according to the invention for preparing compounds of the formula (I).In the formula (III), R³, R⁴ and R⁵ each preferably or in particularhave those meanings which have already been mentioned above inconnection with the description of the compounds of the formula (I)according to the invention as being preferred or as being particularlypreferred for R³, R⁴ and R⁵; R preferably represents alkyl having 1 to 4carbon atoms, in particular methyl or ethyl.

The starting materials of the formula (III) are known chemicals forsynthesis.

The formula (Ia) provides a general definition of the2,4-diamino-1,3,5-triazines to be used as starting materials in theprocess (b) according to the invention for preparing compounds of theformula (I). In the formula (Ia), R¹, R², R³, R⁴ and R⁵ each preferablyor in particular have those meanings which have already been mentionedin connection with the description of the compounds of the formula (I)according to the invention as being preferred or as being particularlypreferred for R¹, R², R³, R⁴ and R⁵.

The starting materials of the general formula (Ia) are, as novelcompounds, also part of the subject-matter of the present application;they can be prepared according to process (a).

The formula (IV) provides a general definition of the alkylating,acylating or sulphonylating agents further to be used as startingmaterials in the process (b) according to the invention for preparingcompounds of the formula (I). In the formula (IV), R⁶ preferably or inparticular has that meaning which has already been mentioned above inconnection with the description of the compounds of the formula (I)according to the invention as being preferred or as being particularlypreferred for R⁶, with the exception of hydrogen; X preferablyrepresents fluorine, chlorine, bromine, iodine, methoxy, ethoxy,acetyloxy, propionyloxy, methoxysulphonyloxy or ethoxysulphonyloxy.

The starting materials of the general formula (VI) are known chemicalsfor synthesis.

The processes according to the invention for preparing the compounds ofthe formula (I) are, if appropriate, carried out using a reactionauxiliary. Suitable reaction auxiliaries for the processes (a) and (b)are the customary inorganic or organic bases or acid acceptors. Thesepreferably include alkali metal or alkaline earth metal acetates,amides, carbonates, bicarbonates, hydrides, hydroxides or alkoxides,such as, for example, sodium acetate, potassium acetate or calciumacetate, lithium amide, sodium amide, potassium amide or calcium amide,sodium carbonate, potassium carbonate or calcium carbonate, sodiumbicarbonate, potassium bicarbonate or calcium bicarbonate, lithiumhydride, sodium hydride, potassium hydride or calcium hydride, lithiumhydroxide, sodium hydroxide, potassium hydroxide or calcium hydroxide,sodium methoxide, ethoxide, n- or -i-propoxide, n-, i-, s- or t-butoxideor potassium methoxide, ethoxide, n- or -i-propoxide, n-, i-, s- ort-butoxide; furthermore also basic organic nitrogen compounds, such as,for example, trimethyl-amine, triethylamine, tripropylamine,tributylamine, ethyl-diisopropylamine, N,N-dimethyl-cyclohexylamine,dicyclohexylamine, ethyl-dicyclohexylamine, N,N-di-methyl-aniline,N,N-dimethyl-benzylamine, pyridine, 2-methyl-, 3-methyl-, 4-methyl-,2,4-dimethyl-, 2,6-dimethyl-, 3,4-dimethyl- and 3,5-dimethyl-pyridine,5-ethyl-2-methyl-pyridine, 4-dimethylamino-pyridine,N-methyl-piperidine, 1,4-di-azabicyclo[2,2,2]-octane (DABCO),1,5-diazabicyclo[4,3,0]-non-5-ene (DBN), or1,8-diazabicyclo[5,4,0]-undec-7-ene (DBU).

Suitable diluents for carrying out the processes (a) and (b) accordingto the invention are, if appropriate, inert organic solvents. Theseinclude, in particular, aliphatic, alicyclic or aromatic, optionallyhalogenated hydrocarbons, such as, for example, benzine, benzene,toluene, xylene, chlorobenzene, dichlorobenzene, petroleum ether,hexane, cyclohexane, dichloromethane, chloroform, carbon tetrachloride;ethers, such as diethyl ether, diisopropyl ether, dioxane,tetrahydrofuran or ethylene glycol dimethyl ether or ethylene glycoldiethyl ether; ketones, such as methyl isopropyl ketone or methylisobutyl ketone; nitriles, such as acetonitrile, propionitrile orbutyronitrile; amides, such as N,N-dimethylformamide,N,N-dimethylacetamide, N-methyl-formanilide, N-methyl-pyrrolidone orhexamethylphosphoric triamide; esters, such as methyl acetate or ethylacetate; sulphoxides, such as dimethyl sulphoxide, alcohols, such asmethanol, ethanol, n- or i-propanol, ethylene glycol monomethyl ether,ethylene glycol monoethyl ether, diethylene glycol monomethyl ether,diethylene glycol monoethyl ether, mixtures thereof with water or purewater.

When carrying out the processes (a) and (b) according to the invention,the reaction temperatures can be varied within a relatively wide range.In general, the reactions are carried out at temperatures between 0° C.and 180° C., preferably between 10° C. and 150° C.

In general, the processes (a) and (b) according to the invention arecarried out at atmospheric pressure. However, it is also possible tocarry out the processes according to the invention under elevated orreduced pressure—in general between 0.1 bar and 10 bar.

To carry out the processes according to the invention, the startingmaterials are generally employed in approximately equimolar amounts.However, it is also possible to use one of the components in arelatively large excess. The reaction is generally carried out in asuitable diluent in the presence of a reaction auxiliary, and thereaction mixture is generally stirred for several hours at thetemperature required. Work-up is carried out according to customarymethods (cf. the Preparation Examples).

The active compounds according to the invention can be used asdefoliants, desiccants, haulm-killers and, especially, as weed-killers.By weeds, in the broadest sense, are to be understood all plants whichgrow in locations where they are undesired. Whether the substancesaccording to the invention act as total or selective herbicides dependsessentially on the amount used.

The active compounds according to the invention can be used, forexample, in connection with the following plants:

Dicotyledonous weeds of the genera: Sinapis, Lepidium, Galium,Stellaria, Matricaria, Anthemis, Galinsoga, Chenopodium, Urtica,Senecio, Amaranthus, Portulaca, Xanthium, Convolvulus, Ipomoea,Polygonum, Sesbania, Ambrosia, Cirsium, Carduus, Sonchus, Solanum,Rorippa, Rotala, Lindernia, Lamium, Veronica, Abutilon, Emex, Datura,Viola, Galeopsis, Papaver, Centaurea, Trifolium, Ranunculus, Taraxacum.

Dicotyledonous crops of the genera: Gossypium, Glycine, Beta, Daucus,Phaseolus, Pisum, Solanum, Linum, Ipomoea, Vicia, Nicotiana,Lycopersicon, Arachis, Brassica, Lactuca, Cucumis, Cucurbita.

Monocotyledonous weeds of the genera: Echinochloa, Setaria, Panicum,Digitaria, Phleum, Poa, Festuca, Eleusine, Brachiaria, Lolium, Bromus,Avena, Cyperus, Sorghum, Agropyron, Cynodon, Monochoria, Fimbristylis,Sagittaria, Eleocharis, Scirpus, Paspalum, Ischaemum, Sphenoclea,Dactyloctenium, Agrostis, Alopecurus, Apera.

Monocotyledonous crops of the genera: Oryza, Zea, Triticum, Hordeum,Avena, Secale, Sorghum, Panicum, Saccharum, Ananas, Asparagus, Allium.

However, the use of the active compounds according to the invention isin no way restricted to these genera, but also extends in the samemanner to other plants.

The compounds are suitable, depending on the concentration, for thetotal control of weeds, for example on industrial terrain and railtracks, and on paths and squares with or without tree plantings.Equally, the compounds can be employed for controlling weeds inperennial cultures, for example forests, decorative tree plantings,orchards, vineyards, citrus groves, nut orchards, banana plantations,coffee plantations, tea plantations, rubber plantations, oil palmplantations, cocoa plantations, soft fruit plantings and hopfields, onlawns, turf and pasture-land, and for the selective control of weeds inannual crops.

The compounds of the formula (I) according to the invention areparticularly suitable for the selective control of monocotyledonous anddicotyledonous weeds in monocotyledonous and dicotyledonous crops byboth the pre- and the post-emergence method.

The active compounds can be converted into the customary formulations,such as solutions, emulsions, wettable powders, suspensions, powders,dusting agents, pastes, soluble powders, granules, suspo-emulsionconcentrates, natural and synthetic materials impregnated with activecompound, and very fine capsules in polymeric substances.

These formulations are produced in a known manner, for example by mixingthe active compounds with extenders, that is liquid solvents and/orsolid carriers, optionally with the use of surface-active agents, thatis emulsifying agents and/or dispersing agents and/or foam-formingagents.

In the case of the use of water as an extender, organic solvents can,for example, also be used as auxiliary solvents. Suitable liquidsolvents are in the main: aromatics, such as xylene, toluene oralkylnaphthalenes, chlorinated aromatics and chlorinated aliphatichydrocarbons, such as chlorobenzenes, chloroethylenes or methylenechloride, aliphatic hydrocarbons, such as cyclohexane or paraffins, forexample petroleum fractions, mineral and vegetable oils, alcohols, suchas butanol or glycol as well as their ethers and esters, ketones, suchas acetone, methyl ethyl ketone, methyl isobutyl ketone orcyclohexanone, strongly polar solvents, such as dimethyl-formamide anddimethylsulphoxide, as well as water.

Suitable solid carriers are: for example ammonium salts and groundnatural minerals, such as kaolins, clays, talc, chalk, quartz,attapulgite, montmorillonite or diatomaceous earth, and ground syntheticminerals, such as finely divided silica, alumina and silicates, suitablesolid carriers for granules are: for example crushed and fractionatednatural rocks such as calcite, marble, pumice, sepiolite, dolomite, aswell as synthetic granules of inorganic and organic meals, and granulesof organic material such as sawdust, coconut shells, maize cobs andtobacco stalks; suitable emulsifying and/or foam-forming agents are: forexample non-ionic and anionic emulsifiers, such as polyoxyethylene fattyacid esters, polyoxyethylene fatty alcohol ethers, for example alkylarylpolyglycol ethers, alkylsulphonates, alkylsulphates, aryl-sulphonates aswell as protein hydrolysates; suitable dispersing agents are: forexample lignin-sulphite waste liquors and methylcellulose.

Tackifiers such as carboxymethylcellulose, natural and syntheticpolymers in the form of powders, granules or lattices, such as gumarabic, polyvinyl alcohol and polyvinyl acetate, as well as naturalphospholipids, such as cephalins and lecithins, and syntheticphospholipids, can be used in the formulations. Further additives can bemineral and vegetable oils.

It is possible to use colorants such as inorganic pigments, for exampleiron oxide, titanium oxide and Prussian blue, and organic dyes, such asalizarine dyes, azo dyes and metal phthalocyanine dyes, and tracenutrients such as salts or iron, manganese, boron, copper, cobalt,molybdenum and zinc.

The formulations in general comprise between 0.1 and 95 per cent byweight of active compound, preferably between 0.5 and 90%.

For controlling weeds, the active compounds according to the invention,as such or in the form of their formulations, can also be used asmixtures with known herbicides, ready-to-use formulations or tank mixesbeing possible.

Possible components for the mixtures are known herbicides, for exampleacetochlor, acifluorfen(-sodium), aclonifen, alachlor,alloxydim(-sodium), ametryne, amidochlor, amidosulfuron, asulam,atrazine, azimsulfuron, benazolin, benfuresate, bensulfuron(-methyl),bentazon, benzofenap, benzoylprop(-ethyl), bialaphos, bifenox,bromobutide, bromofenoxim, bromoxynil, butachlor, butylate, cafenstrole,carbetamide, chlomethoxyfen, chloramben, chloridazon,chlorimuron(-ethyl), chlornitrofen, chlorsulfuron, chlortoluron,cinmethylin, cinosulfuron, clethodim, clodinafop(-propargyl), clomazone,clopyralid, clopyrasulfuron, cloransulam(-methyl), cumyluron, cyanazine,cycloate, cyclosulfamuron, cycloxydim, cyhalofop(-butyl), 2,4-D, 2,4-DB,2,4-DP, desmedipham, diallate, dicamba, diclofop(-methyl), difenzoquat,diflufenican, dimefuron, dimepiperate, dimethachlor, dimethametryn,dimethenamid, dinitramine,diphenamid, diquat, dithiopyr, diuron, dymron,EPTC, esprocarb, ethalfluralin, ethametsulfuron(-methyl), ethofumesate,ethoxyfen, etobenzanid, fenoxaprop(-ethyl), flamprop(-isopropyl),flamprop(-isopropyl-L), flamprop(-methyl), flazasulfuron,fluazifop(-butyl), flumetsulam, flumiclorac(-pentyl), flumioxazin,flumipropyn, fluometuron, fluorochloridone, fluoroglycofen(-ethyl),flupoxam, flupropacil, flurenol, fluridone, fluroxypyr, flurprimidol,flurtamone, fluthiamide, fomesafen, glufosinate(-ammonium),glyphosate(-isopropylammonium), halosafen, haloxyfop(-ethoxyethyl),hexazinone, imazamethabenz(-methyl), imazamethapyr, imazamox, imazapyr,imazaquin, imazethapyr, imazosulfuron, ioxynil, isopropalin,isoproturon, isoxaben, isoxaflutole, isoxapyrifop, lactofen, lenacil,linuron, MCPA, MCPP, mefenacet, metamitron, metazachlor,methabenzthiazuron, metobenzuron, metobromuron, metolachlor, metosulam,metoxuron, metribuzin, metsulfuron(-methyl), molinate, monolinuron,naproanilide, napropamide, neburon, nicosulfuron, norflurazon orbencarb,oryzalin, oxadiazon, oxyfluorfen, paraquat, pendimethalin, phenmedipham,piperophos, pretilachlor, primisulfuron(-methyl), prometryn, propachlor,propanil, propaquizafop, propyzamide, prosulfocarb, prosulfuron,pyrazolate, pyrazosulfuron(-ethyl), pyrazoxyfen, pyributicarb, pyridate,pyrithiobac(-sodium), quinchlorac, quinmerac, quizalofop(-ethyl),quizalofop(-p-tefuryl), rimsulfuron, sethoxydim, simazine, simetryn,sulcotrione, sulfentrazone, sulfometuron(-methyl), sulfosate, tebutam,tebuthiuron, terbuthylazine, terbutryn, thenylchlor, thiazopyr,thidiazimin, thifensulfuron(-methyl), thiobencarb, tiocarbazil,tralkoxydim, triallate, triasulfuron, tribenuron(-methyl), triclopyr,tridiphane, trifluralin and triflusulfuron.

Mixtures with other known active compounds, such as fungicides,insecticides, acaricides, nematicides, bird repellents, plant nutrientsand agents which improve soil structure, are also possible.

The active compounds can be used as such, in the form of theirformulations or in the use forms prepared therefrom by further dilution,such as ready-to-use solutions, suspensions, emulsions, powders, pastesand granules. They are used in the customary manner, for example bywatering, spraying, atomizing or scattering.

The active compounds according to the invention can be applied eitherbefore or after emergence of the plants. They can also be incorporatedinto the soil before sowing.

The amount of active compound used can vary within a substantial range.It depends essentially on the nature of the desired effect. In general,the amounts used are between 1 g and 10 kg of active compound perhectare of soil surface, preferably between 5 g and 5 kg per ha.

The preparation and use of the active compounds according to theinvention can be seen from the examples below.

PREPARATION EXAMPLES EXAMPLE 1

(Process (a))

At 20° C., a solution of 3.5 g (65 mmol) of sodium methoxide in 15 ml ofmethanol is added dropwise with stirring to a mixture of 15.5 g (60mmol) of 1-(1-phenyl-propyl)-biguanide (racemic), 8.0 g (60 mmol) ofethyl 2-fluoro-propanoate and 100 ml of methanol, and the reactionmixture is then stirred for 15 hours at room temperature (about 20° C.).The mixture is then shaken with methylene chloride and water, and theorganic phase is separated off, washed with 1N aqueous sodium hydroxidesolution, dried with sodium sulphate and filtered. The solvent iscarefully distilled off from the filtrate under water pump vacuum.

This gives 13 g (78% of theory) of2-amino-4-(1-fluoro-ethyl)-6-(1-phenyl-propyl-amino)-1,3,5-triazine(racemate) as an amorphous residue.

EXAMPLE 2

(Process (b))

At 130° C., a mixture of 10 g (36 mmol) of2-amino-4-(1-fluoro-ethyl)-6-(1-phenyl-propylamino)-1,3,5-triazine(racemic) and 70 ml of acetic anhydride is stirred for 2 hours and,after cooling to room temperature (about 20° C.), stirred with 150 ml ofwater and 150 ml of methylene chloride. The organic phase is thenseparated off, dried with sodium sulphate and filtered. The filtrate isconcentrated under water pump vacuum, the residue is digested with alittle ethanol and the resulting crystalline product is isolated byfiltration with suction.

This gives 2.2 g (19% of theory) of2-acetylamino-4-(1-fluoro-ethyl)-6-(1-phenyl-propylamino)-1,3,5-triazine(racemate) of melting point 118° C.

By the methods of Preparation Examples 1 and 2, and in accordance withthe general description of the preparation process according to theinvention, it is also possible to prepare, for example, the compounds ofthe formula (I) listed in Table 1 below.

TABLE 1 Examples of compounds of the formula (I) Ex. No. R¹ R² R³ R⁴ R⁵R⁶ Physical data 3

C₂H₅ F F F H (amorphous) (racemate) 4

C₂H₅ F F F COCH₃ m.p.: 112° C. (racemate) 5

C₃H₇-i F F F H (amorphous) (racemate) 6

C₃H₇-i F F F COCH₃ m.p. 134° C. (racemate) 7

C₂H₅ CH₃ CH₃ F H (amorphous) (racemate) 8

C₂H₅ CH₃ CH₃ F COCH₃ m.p. 117° C. (racemate) 9

C₃H₇-i CH₃ F H H (amorphous) (racemate) 10

C₃H₇-i CH₃ CH₃ F H (amorphous) (racemate) 11

C₃H₇-i CH₃ F H COCH₃ m.p.: 98° C. (racemate) 12

C₃H₇-i CH₃ CH₃ F COCH₃ m.p.: 124° C. (racemate) 13

CH₃ CH₃ CH₃ F H n_(D) ²⁰ = 1.5513 (racemate) 14

CH₃ CH₃ CH₃ F H n_(D) ²⁰ = 1.5388 (R enantiomer) 15

CH₃ CH₃ CH₃ F H n_(D) ²⁰ = 1.5450 (S enantiomer) 16

CH₃ CH₃ F H H n_(D) ²⁰ = 1.5472 (racemate) 17

CH₃ CH₃ F H H n_(D) ²⁰ = 1.5430 (S enantiomer) 18

CH₃ CH₃ Cl H H n_(D) ²⁰ = 1.5920 (racemate) 19

CH₃ CH₃ Br H H n_(D) ²⁰ = 1.5715 (racemate) 20

CH₃ CH₃ CH₃ Br H n_(D) ²⁰ = 1.5673 (racemate) 21

CH₃ CH₃ CH₃ CH₃ H n_(D) ²⁰ = 1.5572 (racemate) 22

CH₃ C₂H₅ H H H n_(D) ²⁰ = 1.5640 (racemate) 23

CH₃ F F F H (amorphous) (racemate) 24

CH₃ F F F H (amorphous) (R enantiomer) 25

CH₃ F F F COCH₃ m.p.: 136° C. (S enantiomer) 26

CH₃ F F F COCH₃ m.p.: 136° C. (R enantiomer) 27

C₂H₅ F F F H [α]_(D) ²⁰ = −78° (S enantiomer) 28

C₂H₅ CH₃ F H H [α]_(D) ²⁰ = −80° (S enantiomer) 29

C₂H₅ CH₃ CH₃ F H [α]_(D) ²⁰ = −71° (S enantiomer) 30

C₂H₅ CH₃ H H H [α]_(D) ²⁰ = −80° (S enantiomer) 31

C₂H₅ CH₃ Cl H H [α]_(D) ²⁰ = −76° (S enantiomer) 32

C₂H₅ Cl Cl H H [α]_(D) ²⁰ = −81° (S enantiomer) 33

C₂H₅ F F F COCH₃ [α]_(D) ²⁰ = −69° (S enantiomer) 34

C₂H₅ CH₃ F H COCH₃ [α]_(D) ²⁰ = −57° (S enantiomer) 35

C₂H₅ CH₃ CH₃ F COCH₃ [α]_(D) ²⁰ = −53° (S enantiomer) 36

C₂H₅ CH₃ H H COCH₃ [α]_(D) ²⁰ = −56° (S enantiomer) 37

C₂H₅ CH₃ Cl H COCH₃ [α]_(D) ²⁰ = −64° (S enantiomer) 38

C₂H₅ Cl Cl H COCH₃ [α]_(D) ²⁰ = −65° (S enantiomer) 39

C₂H₅ CH₃ F H H [α]_(D) ²⁰ = +118.5° (R enantiomer) 40

C₂H₅ CH₃ F H H (amorphous) (racemate) 41

C₂H₅ CH₃ CH₃ F H (amorphous) (racemate) 42

C₃H₇-i CH₃ F H COCH₃ (amorphous) (R enantiomer) 43

C₃H₇-i CH₃ F H COCH₃ (amorphous) (S enantiomer) 44

C₃H₇-i CH₃ CH₃ F COCH₃ (amorphous) (R enantiomer) 45

C₃H₇-i CH₃ CH₃ F COCH₃ (amorphous) (S enantiomer) 46

C₂H₅ CH₃ CH₃ F H [α]_(D) ²⁰ = +80.0° (R enantiomer) 47

C₃H₇-i CH₃ F H H (amorphous) (R enantiomer) 48

C₃H₇-i CH₃ F H H (amorphous) (S enantiomer) 49

C₃H₇-i CH₃ CH₃ F H (amorphous) (R enantiomer) 50

C₃H₇-i CH₃ CH₃ F H (amorphous) (R-Enantiomer) 51

C₂H₅ F F F H [α]_(D) ²⁰ = +103.5° (R enantiomer) 52

C₂H₅ CH₃ H H H [α]_(D) ²⁰ = +98.9° (R enantiomer) 53

C₂H₅ CH₃ Cl H H [α]_(D) ²⁰ = +89.0° (R enantiomer) 54

C₂H₅ Cl Cl H H [α]_(D) ²⁰ = +86.1° (R enantiomer) 55

C₂H₅ F F F COCH₃ [α]_(D) ²⁰ = +72.2° (R enantiomer) 56

C₂H₅ CH₃ F H COCH₃ [α]_(D) ²⁰ = +91.5° (R enantiomer) 57

C₂H₅ CH₃ CH₃ F COCH₃ [α]_(D) ²⁰ = 65.2° (R enantiomer) 58

C₂H₅ CH₃ H H COCH₃ [α]_(D) ²⁰ = +70.0° (R enantiomer) 59

C₂H₅ CH₃ Cl H COCH₃ [α]_(D) ²⁰ = +76.4° (R enantiomer) 60

C₂H₅ Cl Cl H COCH₃ [α]_(D) ²⁰ = +75.7° (R enantiomer) 61

CH₃ OCH₃ H H H m.p.: 85° C. (racemate) 62

C₂H₅ CH₃ H H H m.p.: 70° C. (racemate) 63

C₂H₅ CH₃ Cl H H m.p.: 60° C. (racemate) 64

C₂H₅ CH₃ Br H H (amorphous) (racemate) 65

C₃H₇-n CH₃ F H H (amorphous) (racemate) 66

C₃H₇-n CH₃ CH₃ F H (amorphous) (racemate) 67

CH₃ CH₃ CH₃ F COCH₃ (amorphous) (S enantiomer) 68

CH₃ CH₃ CH₃ F COC₂H₅ (amorphous) (S enantiomer) 69

CH₃ CH₃ CH₃ H H n_(D) ²⁰ = 1.5649 (racemate) 70

CH₃ CF₃ F F H n_(D) ²⁰ = 1.5084 (racemate) 71

CH₃ CH₂OCH₃ H H H n_(D) ²⁰ = 1.5683 (racemate) 72

CH₃ F H H H m.p.: 166° C. (racemate) 73

CH₃ H H H H (amorphous) (S enantiomer) 74

CH₃ CH₃ H H H (amorphous) (S enantiomer) 75

CH₃ OCH₃ H H H (amorphous) (S enantiomer) 76

CH₃ Cl Cl H H (amorphous) (S enantiomer) 77

C₃H₇-n CH₃ F H COC₂H₅ n_(D) ²⁰ = 1.5416 (racemate) 78

C₃H₇-n CH₃ CH₃ F COC₂H₅ n_(D) ²⁰ = 1.5399 (racemate) 79

C₂H₅ CH₃ F H COC₂H₅ [α]_(D) ²⁰ = −66.02° (S enantiomer) 80

C₂H₅ CH₃ F H COC₃H₇-n [α]_(D) ²⁰ = −64.25° (S enantiomer) 81

C₂H₅ CH₃ F H COCH(CH₃)₂ [α]_(D) ²⁰ = −61.03° (S enantiomer) 82

C₂H₅ CH₃ F H COCH₂CH(CH₃)₂ [α]_(D) ²⁰ = −60.96° (S enantiomer)

Starting Materials of the Formula (II) EXAMPLE (II-1)

A mixture of 27 g (0.21 mol) of 1-phenyl-ethylamine (racemic), 22 ml of33% strength aqueous hydrochloric acid and about the same amount oftoluene is concentrated to dryness under water pump vacuum. 17 g (0.21mol) of dicyanodiamide (cyanoguanidine) are added to the residue, andthe mixture is then heated at 150° C. for two hours, giving a melt.

The resulting crude product—1-(1-phenyl-propyl)-biguanide hydrochloride(racemic)—is employed directly for preparing compounds of the formula(I).

By the method of Example (II-1) it is also possible to prepare, forexample, the compounds of the formula (II) listed in Table 2 below orhydrochlorides thereof.

TABLE 2 Examples of compounds of the formula (II) Ex. No. R¹ R² R⁶Melting point (° C.) II-2

C₃H₇-i H 190 (hydrochloride) (racemate) II-3

CH₃ H (amorphous) (hydrochloride) (racemate) II-4

C₃H₇-n H (amorphous) (hydrochloride) (racemate) II-5

C₂H₅ H (amorphous) (hydrochloride) (S enantiomer) II-6

C₂H₅ H (amorphous) (hydrochloride) (R enantiomer) II-7

CH₃ H (amorphous) (hydrochloride) (R enantiomer)

USE EXAMPLES

The known compound (A) is used as comparative substance in the useexamples below:

2-Amino-4-(1-phenyl-ethylamino)-6-trifluoromethyl-1,3,5-triazine (cf.U.S. Pat. No. 3,816,419)

EXAMPLE A Pre-emergence Test

Solvent: 5 parts by weight of acetone

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, 1 part by weightof active compound is mixed with the stated amount of solvent, thestated amount of emulsifier is added and the concentrate is diluted withwater to the desired concentration.

Seeds of the test plants are sown in normal soil. After about 24 hours,the soil is sprayed with the preparation of active compound in such away that the particular amounts of active compound desired are employedper unit area. The concentration of the spray liquor is chosen such thatthe particular amounts of active compound desired are applied in 1000 lof water/ha.

After three weeks, the degree of damage to the plants is assessed in %damage in comparison to the development of the untreated control.

The figures denote:

0%=no effect (as untreated control) 100%=total destruction

In this test, for example, the compounds of Preparation Example 1, 2,13, 14, 15, 16, 17 and 18 exhibit considerably strong action againstweeds than the known compound (A) -cf. Table A -, and some of them aretolerated well by crop plants, such as, for example, cotton, barley andrapeseed.

“ai”=“active ingredient”

TABLE A Pre-emergence test/greenhouse Application Active compound ofpreparation Ex. No. rate (g of ai./ha) Alopecurus Avena fatua AbutilonAmaranthus Galium Xanthium

1000  30  0  0  70  60  70 (A)

1000 100 70 70 100 100 100 (1) Application Active compound ofpreparation Ex. No. rate (g of ai./ha) Alopecurus Setaria AbutilonAmaranthus

1000 30 20  0  70 (A)

1000 90 70 100 100 (2) Application Active compound of preparation Ex.No. rate (g of ai./ha) Reapseed Amaranthus Chenopodium Datura MatricariaSolanum

125 40  40  20  0  0  0 (A)

125  0 100 100 95 95 95 (14) Application Active compound of preparationEx. No. rate (g of ai./ha) Barley Cotton Veronica Viola

250 0 0  20  0 (A)

250 0 0 100 100 (15) Application Active compound of preparation Ex. No.rate (g of ai./ha) Alopecurus Avena fatua Abutilon Amaranthus VeronicaViola

250 30  0  0 80  20  0 (A)

250 80 80 80 95 100 95 (17) Application Active compound of preparationEx. No. rate (g of ai./ha) Alopecurus Avena fatua Setaria Cassia IpomoeaViola

250 30  0  0  20 20  0 (A)

250 90 90 80 100 80 100 (13) Application Alope- Active compound ofpreparation Ex. No. rate (g of ai./ha) curus Lolium Sorghum AbutilonAmaranthus Cassia Ipomoea

250  30  0  0  0  80  20  20 (A)

250 100 100 95 80 100 100 100 (16) Application Active compound ofpreparation Ex. No. rate (g of ai./ha) Reapseed Amaranthus Ipomoea

250 40  80 20 (A)

250  0 100 95 (18)

EXAMPLE B Post-emergence Test

Solvent: 5 parts by weight of acetone

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, 1 part by weightof active compound is mixed with the stated amount of solvent, thestated amount of emulsifier is added and the concentrate is diluted withwater to the desired concentration.

Test plants which have a height of 5 to 15 cm are sprayed with thepreparation of active compound in such a way that the particular amountsof active compound desired are applied per unit area. The concentrationof the spray liquor is chosen such that the particular amounts of activecompound desired are applied in 1000 l of water/ha.

After three weeks, the degree of damage to the plants is assessed in %damage in comparison to the development of the untreated control.

The figures denote:

0%=no effect (as untreated control)

100%=total destruction

In this test, for example, the compounds of Preparation Example 1, 2, 13and 18 exhibit considerably stronger activity against weeds than theknown compound (A) -cf. Table B -, and some of them are tolerated wellby crop plants, such as, for example, wheat and barley.

TABLE B Post-emergence test/greenhouse Application Active compound ofpreparation Ex. No. rate (g of ai./ha) Cassia Ipomoea MatricariaVeronica

125 80  90 60  90 (A)

125 90 100 80 100 (1) Application Active compound of preparation Ex. No.rate (g of ai./ha) Ipomoea Polygonum Solanum Veronica

60  80  80 40 70 (A)

60 100 100 95 95 (1) Application Active compound of preparation Ex. No.rate (g of ai./ha) Echinochloa Setaria Cassia Ipomoea MatricariaVeronica Xanthium

125 50 50  80  90 60 90 60 (A)

125 80 80 100 100 95 95 80 (2) Application Active compound ofpreparation Ex. No. rate (g of ai./ha) Wheat Cassia Solanum Veronica

60 0 40 40 70 (A)

60 0 70 90 95 (18) Application Active compound of preparation Ex. No.rate (g of ai./ha) Barley Wheat Cassia Ipomoea Veronica

125 5 0 80  90  90 (A)

125 0 0 95 100 100 (13)

What is claimed is:
 1. A compound of the formula (I)

wherein R¹ represents unsubstituted phenyl, R² represents alkyl having 1to 6 carbon atoms, R³ represents unsubstituted, fluoro- ormethoxy-substituted methyl or unsubstituted ethyl, R⁴ representshydrogen or methyl, R⁵ represents fluorine, and R⁶ represents hydrogenor represents unsubstituted or halogen- or C₁-C₄-alkoxy substitutedC₁-C₆-alkyl, C₂-C₇-alkylcarbonyl or C₁-C₆-alkylsulphonyl.
 2. A compoundof the formula (I) according to claim 1, wherein R¹ representsunsubstituted phenyl, R² represents alkyl having 1 to 6 carbon atoms, R³represents unsubstituted, fluoro- or methoxy-substituted methyl orunsubstituted ethyl, R⁴ represents hydrogen or methyl, R⁵ representsfluorine, and R⁶ represents hydrogen or represents in each caseunsubstituted or halogen- or C₁-C₄-alkoxy substituted C₁-C₆-alkyl orC₂-C₇-alkyl-carbonyl.
 3. A compound of the formula (I) according toclaim 1, wherein R¹ represents unsubstituted phenyl, R² representsmethyl, ethyl, n- or i-propyl, n-, i-, s- or t-butyl, R³ representsunsubstituted, fluoro- or methoxy-substituted methyl or unsubstitutedethyl, R⁴ represents hydrogen, R⁵ represents fluorine, and R⁶ representshydrogen or represents in each case optionally fluorine-, chlorine-,methoxy- or ethoxy-substituted methyl, ethyl, n- or i-propyl, n-, i-, s-or t-butyl, acetyl, propionyl, n- or i-butyroyl, methylsulphonyl,ethylsulphonyl, n- or i-propylsulphonyl, n-, i-, s- or t-butylsulphonyl.4. A herbicidal composition comprising one or more compounds of theformula (I) according to claim 1 and extenders and/or surfactants.
 5. Amethod for controlling weeds and/or undesirable vegetation comprisingapplying an effective amount of one or more compounds of the formula (I)according to claim 1 to the weeds or their habitat.
 6. A compound of theformula (I) according to claim 1, wherein R⁶ represents halogen- orC₁-C₄-alkoxy substituted C₁-C₆-alkyl or represents unsubstituted orhalogen- or C₁-C₄-alkoxy substituted C₂-C₇-alkyl-carbonyl orC₁-C₆-alkylsulphonyl.
 7. A compound of the formula (I) according toclaim 1, wherein R³ represents unsubstituted, fluoro- ormethoxy-substituted methyl.
 8. A compound of the formula (I)

wherein R¹ represents unsubstituted phenyl, R² represents ethyl, n- ori-propyl, n-, i-, s- or t-butyl, R³ represents unsubstituted, fluoro- ormethoxy-substituted methyl or unsubstituted ethyl, R⁴ representshydrogen or methyl, R⁵ represents fluorine, and R⁶ represents hydrogenor represents unsubstituted or halogen- or C₁-C₄-alkoxy substitutedC₁-C₆-alkyl, C₂-C₇-alkylcarbonyl or C₁-C₆-alkylsulphonyl.
 9. A compoundof the formula (I) according to claim 1, wherein when R² representsmethyl then R⁶ is other than hydrogen.
 10. A compound of the formula (I)according to claim 1, wherein when R² represents methyl then R⁶represents unsubstituted or fluorine-, chlorine methoxy- orethoxy-substituted methyl, ethyl, n- or i-propyl, n-, i-, s- or t-butyl,acetyl, propionyl, n- or i-butyroyl, methylsulphonyl, ethylsulphonyl, n-or i-propylsulphonyl, n-, i-, s- or t-butylsulphonyl.
 11. A compound ofthe formula (I) according to claim 1, wherein R³ represents methyl, R⁴represents hydrogen, and R⁵ represents fluorine.
 12. A compound of theformula (I) according to claim 13, wherein R³ represents methyl, R⁴represents hydrogen, and R⁵ represents fluorine.
 13. A compound of theformula (I)

wherein R¹ represents unsubstituted phenyl, R² represents ethyl, n- ori-propyl, n-, i-, s- or t-butyl, R³ represents unsubstituted or halogen-or C₁-C₄-alkoxy-substituted alkyl having 1 to 6 carbon atoms, R⁴represents hydrogen or represents unsubstituted C₁-C₆-alkyl, R⁵represents halogen, and R⁶ represents unsubstituted or C₁-C₄-alkoxysubstituted C₁-C₆-alkyl, unsubstituted or halogen- or C₁-C₄-alkoxysubstituted C₂-C₇-alkyl-carbonyl or unsubstituted or halogen- orC₁-C₄-alkoxy substituted C₁-C₆-alkylsulphonyl.
 14. A compound accordingto claim 13, wherein R³ represents methyl, R⁴ represents hydrogen, andR⁵ represents fluorine.